Rapid exchange balloon dilation catheter having reinforced multi-lumen distal portion

Abstract

A rapid exchange balloon dilation catheter includes a catheter shaft with a proximal tubular member defining a proximal inflation/deflation lumen for conveying fluids therethrough with a distal portion of the bore of proximal tubular member filled with a fluid-impervious barrier, a distal body extending from the fluid-impervious barrier to the distal end of the shaft, a plurality of distal tubular members defining distal inflation/deflation lumens in fluid communication with the proximal inflation/deflation lumen and extending through the fluid-impervious barrier and the distal body to the distal end of the shaft distal portion, a guidewire tubular member having a bore extending from a side aperture formed in the distal body through the distal body alongside the distal tubular members in a multi-lumen arrangement, and a plurality of stiffening members extending from within the fluid-impervious barrier into the distal body to a point within the shaft distal portion.

What is claimed is: 
     
       1. A rapid exchange balloon dilation catheter adapted to be utilized with a guidewire, the catheter comprising:
 an elongated catheter shaft having a shaft proximal portion, a shaft distal portion, and a shaft transitional portion disposed therebetween, each of the proximal, distal and transitional shaft portions having a proximal end and a distal end; 
 a balloon having a proximal end, a distal end and an interior, the proximal end of the balloon being attached to the distal end of the shaft distal portion; 
 the catheter shaft including
 a proximal tubular member having a bore and extending from the proximal end of the shaft proximal portion into the shaft transitional portion, the proximal portion of the bore defining a proximal inflation/deflation lumen for conveying fluids therethrough and the distal portion of the bore being filled with a fluid-impervious barrier; 
 a distal body extending from the fluid-impervious barrier to the distal end of the shaft distal portion; 
 a plurality of distal tubular members, each distal tubular member having a bore and extending from the proximal inflation/deflation lumen through the fluid-impervious barrier and the distal body to the distal end of the shaft distal portion, the bores of the distal tubular members defining distal inflation/deflation lumens for conveying fluids therethrough, the distal inflation/deflation lumens being in fluid communication with the proximal inflation/deflation lumen at their proximal ends and with the interior of the balloon at their distal ends; 
 a guidewire tubular member having a bore and originating from a side aperture formed in the distal body, extending through the distal body alongside the distal tubular members in a multi-lumen arrangement, then through the interior of the balloon to the distal end of the balloon, the bore of the guidewire tubular member defining a guidewire lumen for conveying a guidewire through the shaft distal portion and the balloon; and 
 a plurality of stiffening members, each stiffening member extending from within the fluid-impervious barrier and into the distal body to a respective point within the shaft distal portion. 
 
 
     
     
       2. A catheter in accordance with  claim 1 , wherein the distal tubular members are formed of polyimide plastic. 
     
     
       3. A catheter in accordance with  claim 2 , wherein the distal body is formed of a polyether block amide (PEBA) thermoplastic elastomer. 
     
     
       4. A catheter in accordance with  claim 3 , wherein the PEBA of the distal body is loaded with approximately 20% (by weight) bismuth. 
     
     
       5. A catheter in accordance with  claim 3 , wherein the proximal tubular member is formed of a polyether block amide (PEBA) thermoplastic elastomer. 
     
     
       6. A catheter in accordance with  claim 1 , wherein the distal body becomes more flexible as it gets closer to the shaft distal end. 
     
     
       7. A catheter in accordance with  claim 6 , wherein at least one of the stiffening members has a different length from other stiffening members. 
     
     
       8. A catheter in accordance with  claim 6 , wherein at least one of the stiffening members has a cross section that varies along its length. 
     
     
       9. A catheter in accordance with  claim 1 , wherein the fluid-impervious barrier is formed with an adhesive and wherein the adhesive surrounds an outside surface of the distal tubular members and an outside surface of the stiffening members with the distal tubular members extending through the adhesive substantially parallel to the stiffening members. 
     
     
       10. A catheter in accordance with  claim 1 , wherein the distal body and proximal tubular member each comprise proximal and distal ends and wherein the proximal end of the distal body is tapered to fit into the distal end of the proximal tubular member. 
     
     
       11. A catheter in accordance with  claim 1 , wherein the side aperture is formed in the shaft transitional portion and wherein the guidewire tubular member extends continuously from the shaft transition portion thorough the shaft distal portion. 
     
     
       12. A shaft for a rapid exchange balloon dilation catheter to be utilized with a guidewire, the shaft comprising:
 a shaft proximal portion, a shaft distal portion, and a shaft transitional portion disposed therebetween, each of the proximal, distal and transitional shaft portions having a proximal end and a distal end; 
 a proximal tubular member having a bore and extending from the proximal end of the shaft proximal portion into the shaft transitional portion, the proximal portion of the bore defining a proximal inflation/deflation lumen for conveying fluids therethrough and the distal portion of the bore being filled with a fluid-impervious barrier; 
 a distal body extending from the fluid-impervious barrier to the distal end of the shaft distal portion; 
 a plurality of distal tubular members, each distal tubular member having a bore and extending from the proximal inflation/deflation lumen through the fluid-impervious barrier and the distal body to the distal end of the shaft distal portion, the bores of the distal tubular members defining distal inflation/deflation lumens for conveying fluids therethrough, the distal inflation/deflation lumens being in fluid communication with the proximal inflation/deflation lumen at their proximal ends and having a fluid passage at their distal ends for conveying fluids out of the distal end of the shaft distal portion; 
 a guidewire tubular member having a bore and originating from a side aperture formed in the distal body, extending through the distal body alongside the distal tubular members in a multi-lumen arrangement, then extending beyond the distal end of the distal body, the bore of the guidewire tubular member defining a guidewire lumen for conveying a guidewire through the shaft distal portion; and 
 a plurality of stiffening members, each stiffening member extending from within the fluid-impervious barrier and into the distal body to a respective point within the shaft distal portion. 
 
     
     
       13. A shaft in accordance with  claim 12 , wherein the distal end of the shaft distal portion is adapted for connection to a proximal end of a dilation balloon, and the portion of the guidewire tubular member extending beyond the distal end of the shaft distal portion is adapted to pass through the interior of the dilation balloon and to be connected to the distal end of the balloon. 
     
     
       14. A shaft in accordance with  claim 12 , wherein the guidewire tubular member is formed of polyimide plastic. 
     
     
       15. A shaft in accordance with  claim 12 , wherein there are at least two distal tubular members. 
     
     
       16. A shaft in accordance with  claim 15 , wherein the distal tubular members are formed of polyimide plastic. 
     
     
       17. A shaft in accordance with  claim 12 , wherein the distal body is formed of a polyether block amide (PEBA) thermoplastic elastomer. 
     
     
       18. A shaft in accordance with  claim 12 , wherein the lateral flexibility of the distal body increases toward the shaft distal end. 
     
     
       19. A shaft in accordance with  claim 18 , wherein at least one of the stiffening members extends distally past the side aperture a different distance from another of the stiffening members. 
     
     
       20. A shaft in accordance with  claim 18 , wherein at least one of the stiffening members has a cross section that varies along its length. 
     
     
       21. A shaft in accordance with  claim 12 , wherein the stiffening members do not include continuous bores for conveying fluids therethrough. 
     
     
       22. A catheter in accordance with  claim 12 , wherein the fluid-impervious barrier is formed with an adhesive and wherein the adhesive surrounds an outside surface of the distal tubular members and an outside surface of the stiffening members with the distal tubular members extending through the adhesive substantially parallel to the stiffening members. 
     
     
       23. A catheter in accordance with  claim 12 , wherein the distal body and proximal tubular member each comprise proximal and distal ends and wherein the proximal end of the distal body is tapered to fit into the distal end of the proximal tubular member. 
     
     
       24. A catheter in accordance with  claim 12 , wherein the side aperture is formed in the shaft transitional portion and wherein the guidewire tubular member extends continuously from the shaft transition portion thorough the shaft distal portion. 
     
     
       25. A shaft for a balloon dilation catheter to be utilized with a guidewire, the shaft comprising:
 a shaft proximal portion including a proximal tubular member having a bore defining a proximal inflation/deflation lumen; 
 a shaft transitional portion connected to a distal end of the shaft proximal portion and including a plurality of distal tubular members and a plurality of stiffening members, the proximal ends of the distal tubular members and the stiffening members being attached to an inner distal surface of the proximal tubular member by a fluid-impervious barrier, each distal tubular member having a bore defining a distal inflation/deflation lumen, and a proximal end of each distal inflation/deflation lumen being in fluid communication with a distal end of the proximal inflation/deflation lumen; 
 a shaft distal portion connected to a distal end of the shaft transitional portion and including a distal body and a guidewire tubular member;
 the distal body encasing the guidewire tubular member and portions of the distal tubing members and the stiffening members, which run alongside one another through the distal body in a multi-lumen arrangement; 
 
 the guidewire tubular member having a bore and extending from a side aperture formed in the distal body to beyond the end of the distal body, the bore of the guidewire tubular member defining a guidewire lumen for conveying a guidewire therethrough;
 the distal tubing members extending to the distal end of the distal body, the distal ends of the distal inflation/deflation lumens forming fluid outlets; 
 the stiffening members extending to points disposed between the side aperture and the distal end of the distal body. 
 
 
     
     
       26. A shaft in accordance with  claim 25 , wherein the distal end of the shaft distal portion is adapted for connection to a proximal end of a dilation balloon, and the portion of the guidewire tubular member extending beyond the distal end of the shaft distal portion is adapted to pass through the interior of the dilation balloon and to be connected to the distal end of the balloon. 
     
     
       27. A shaft in accordance with  claim 25 , wherein the lateral stiffness of the distal body decreases between the side aperture and the distal end. 
     
     
       28. A shaft in accordance with  claim 27 , wherein the lateral stiffness of the distal body decreases at a plurality of discrete points between the side aperture and the distal end. 
     
     
       29. A shaft in accordance with  claim 28 , wherein at least one of the stiffening members terminates at each of the discrete points at which the lateral stiffness of the distal body decreases. 
     
     
       30. A catheter in accordance with  claim 25 , wherein the fluid-impervious barrier is formed with an adhesive and wherein the adhesive surrounds an outside surface of the distal tubular members and an outside surface of the stiffening members with the distal tubular members extending through the adhesive substantially parallel to the stiffening members. 
     
     
       31. A catheter in accordance with  claim 25 , wherein the distal body and proximal tubular member each comprise proximal and distal ends and wherein the proximal end of the distal body is tapered to fit into the distal end of the proximal tubular member. 
     
     
       32. A catheter in accordance with  claim 25 , wherein the side aperture is formed in the shaft transitional portion and wherein the guidewire tubular member extends continuously from the shaft transition portion thorough the shaft distal portion.